Well, it could mean that in the context of Percy Jackson, something about Percy Jackson's character or actions in a fan - created story (fanfic) disrupts or spoils what was otherwise a really good or well - structured fanfic. Maybe his actions go against the flow or theme the fanfic author had in mind.
It's a rather odd statement. 'Harry' here might refer to a character named Harry in a particular fandom. 'Ruins' implies that he somehow spoils or negatively impacts a 'fanfic' (fan fiction). However, 'tight ass' is an inappropriate and unclear part in this context. It could be a very unorthodox or poorly worded description within the fan - created story.
Another example could be if the fanfic was about a group of characters trying to solve a complex mystery in a particular way. Percy Jackson shows up and uses his typical 'go - it - alone' style that is so characteristic of him in the original books. This might undermine the group dynamic that the fanfic writer was trying to establish, and make the whole mystery - solving process seem too easy or forced, thus ruining the fanfic.
It's difficult to say exactly. 'Harry' is likely a character in a fanfic. When it says he 'ruins' it, he probably does something that goes against what the fanfic was supposed to be about or what the fans expected. But the 'tight ass' part is inappropriate and doesn't seem to have a proper meaning in this context. Maybe it was just a random or wrong choice of words by the person who came up with this statement.
It could mean that Percy, perhaps a character or a person, is ruining or disrupting a very good or well - constructed fanfic. Maybe Percy has some sort of action or behavior that goes against the plot, characters, or themes of the fanfic, thus 'destroying' it in a sense.
If Percy is a character, he might destroy the fanfic out of jealousy. Maybe the fanfic is getting more attention than he is used to, so he takes actions to undermine it.
There's no way to know for sure who Harry is just from this title. He could be an original character created for the fanfic, or he could be a character borrowed from another work and being used in a new way within this fan - created story.
I'm not sure specifically as it's an odd title. It could potentially be about a character named Harry who is making changes or having an impact on a fan - created story related to something described as 'tight ass'. But without more context, it's really hard to say.
Well, it could imply that in a Naruto - related fan - created story (fanfic), Naruto somehow causes destruction within a situation that is very difficult or 'tight' in the context of the fanfic's plot. But without more context, it's really hard to be specific.